$ strace -f -e clone,execve perl -e'open(my $fh, "|-", "nonexistent program 2>/dev/null")'
execve("/usr/bin/perl", ["perl", "-eopen(my $fh, \"|-\", \"nonexisten"...], [/* 45 vars */]) = 0
clone(Process 7809 attached
child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb753ea68) = 7809
[pid  7809] execve("/bin/sh", ["sh", "-c", "nonexistent program 2>/dev/null"], [/* 45 vars */]) = 0
[pid  7809] +++ exited with 127 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=7809, si_uid=1000, si_status=127, si_utime=0, si_stime=0} ---
+++ exited with 0 +++